Windows XP Pro-Entire Network icon issue

I have 30 IBM desktops (brand new, preloaded XP Pro) and they cannot use My Network Places/Entire Network. When you double click on My Network Places, then click on Entire Network–it just hangs on each system. All systems are up to date with Symantec’s AV/Windows Updates/SP1 (or 2)/Spybot Search and Destroy and all just deployed. Don’t have this problem on our laptops (600 imaged using Ghost), but any help appreciated as \\servername\sharedfolder from the Start..Run is fine and all configurations for DHCP, etc. are correct. No errors in Event Viewer and Device Manager is clean. Thanks!